Section 347 of the 2012 National Defense Authorization Act called on the Department of Defense to commission an independent assessment of the overseas basing presence of U.S. military forces. As the recipient of that commission, RAND’s National Defense Research Institute conducted an independent assessment of the advisability of changes in the overseas basing presence of U.S. forces based on an evaluation of strategic benefits, risks, and costs. The report characterizes how overseas presence contributes to assurance of allies, deterrence, contingency responsiveness, and security cooperation, along with the risks involved with investing in facilities overseas. It breaks new ground in the understanding of the costs associated with overseas presence, including how permanent and rotational presence costs compare, and provides cost models for policymakers to weigh alternative posture options. To support this understanding of costs the report also lays out the conditions of U.S. installations and levels of host nation support.

The report concludes that there are certain minimum requirements necessary to carry out the current national security strategy, but it is prudent, based upon the net value produced, to maintain an overseas posture that goes beyond these minimums. Additionally, it combines benefit, cost, and risk considerations to distill a number of strategic judgments that have implications for the advisability of considering identified posture changes. …